linux-kernel - Re: [PATCH] Ensure that walk_page_range()'s start and end are page-aligned

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite for Android: free password hash cracker in your pocket

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:	Tue, 14 Feb 2012 06:59:51 -0800
From:	Dan Smith <danms@...ibm.com>
To:	David Rientjes <rientjes@...gle.com>
Cc:	akpm@...ux-foundation.org, linux-mm@...ck.org,
	linux-kernel@...r.kernel.org
Subject: Re: [PATCH] Ensure that walk_page_range()'s start and end are page-aligned

DR> That's not a precedent, there's a big difference between the
DR> performance of gup_fast(), where we can't spare an additional
DR> compare and branch, and walk_page_range().  VM_BUG_ON() is typically
DR> used in situations where a debug kernel has been built, including
DR> CONFIG_DEBUG_VM, and the check helps to isolate a problem that would
DR> be otherwise difficult to find.

Okay, fair enough. I was trying to stay in line with the other
conventions, knowing that the check would only be done with
CONFIG_DEBUG_VM enabled.

I'd rather just make it always do the check in walk_page_range(). Does
that sound reasonable?

-- 
Dan Smith
IBM Linux Technology Center
email: danms@...ibm.com
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/